Electric-incandescent-lamp holder.



No. 70|,949. Patented June It), I902; j

E. G.- SHEPPARD v ELECTRIC INGAND'ESGENT LAMP HOLDER (Application filed Dec. 11, 1900.)

(No Model.)

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I UNITED "STATES EUSTAOE GRAHAMSHEPPARD, or LONDON, ENGLAND, ASSIGNOROF ONE PATENT. OFFICE.

' HALF TO NERNST ELECTRIC LIGHT, LIMITED, OF LONDON, ENGLAND.

ELECTRIC-lNCAN DESCENT-LAMP HOLDER.

SPECIFICATION formingpart of Letters Patent No. 701,949, dated June l0, 1902. Application filed December 11,1900. Serial No. 39,470. (No model.

To all whom it may concern:

Beit known that I, EUSTACE GRAHAM SHEP- PARD, electrician, a subject of the Queen of lamp or filament holders where three contacts require to be made in" a reliable and simple manner and is especiallyapplicable for use in Nernst lamps. In such lamps 1t becomes advantageous to make provision for the replacement of theworn-out filaments from the center, such that when corresponding contact-pieces similarly arranged on an insulating bridge-piece carrying the filament are placed into engagement with the first set' of contact-pieces it is only possible for them to engage to close the electric circuit in one way-that is, only the proper terminals can touch or engage with one another. The engagement which takes place between the terminals is such that they become mechanically locked with a positive pressure, insuring electric contact at all three points.

Referring now to the accompanying sheet of drawings, Figure 1 is a central section of one modification of my improved lamp-holder applied to a Nernst lamp-which is represented in diagram. Fig. 2,is a side elevation of thesame without the Nernst lamp. Figs. 3 and 4. are. front elevations showing other modifications of the holder, and-Fig. 5 is a front elevation of a fourth modification.

The same letters of reference are used to indicate similar parts in diflerent figures of the drawings. F v

. I'ncarrying my invention into. effect, as illustrated'iuFigs. 1 and 2, I- provide on the permanent base a, threecontaet-pillars b, c, and d, situated alongadiame'trieline across the base, the pillar I) placed at or near the center and the pillars c and'd on'-opposite sides of, but at'ditferent distances from, the lpillar b. The pillar blprovide'with a spring- 7 pressed plunger e, andthe pillars c and d I provide with hooks f, facing-in opposite directions. In an insulatingbridge-piece g, carrying the filament 'n and other parts of a Nernst lamp, as indicated in Fig. 1, I provide three terminals or contact-pieeesh, i, and j,

passing through it and situated in the saidbridge-piece in positions corresponding to those of b, o, and d in the permanent base a. The two terminals or contact-pieces i and j areformed with eyes is, adapted to engage with the hooked terminals 0 and d.

One end of the terminal or contact-piece It forms thebottom of a socket l, intowhich the 'plungere of the contact-pillar b is adapted to fit," so that a spring-pressed contact may be made at the bottom of the socket. The socket l is formed, preferably, of insulating m at erial.

To 'make the electrical connection between the contacts I), c, and d on the base a and the contacts h, 11, and on the bridge-piece g, the latter is brought near to the base, with the spring-pressed plunger e passing into the socket l. The bridge-piece g is then pressed toward the base or, pushing back the plunger e till the eyes 70 come into the same plane as the hooks f. The bridge-piece g is then.

turned around till the hooks f project through described connection is being efi ecited the bridge-piece g would bepresed* to'wai'd the base a at a slight angle and straightened to roe pass the eyes 70 on to the hooks f, or the said contact-pillars may each be provided with double hooks facing both ways, either outward, as shown in Fig. 3, orinward, as shown in Fig. 4, so that the bridge-piece 9 can be hooked to the base a by giving it a turn in either a right or left hand direction.

It will be obvious that various modifications may be made without departing from my inventionf0r example, as shown in Fig. 5, the outer terminals or contact-pieces might be provided with springpressed plungers e and the center one formed with a hook f, adapted to engage with an eye 70 on the corresponding terminal oi the bridge-piece g.

Having now described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. In an electric-incandescent-lamp holder the combination with two separable members of two hook-and-eye electric contacts coupling the members together and limiting the distance which they can move apart, and eccentrically arranged between them, a springpressed electric contact forcing the said members apart substantially as set forth.

2. In an electric-incandescent-lamp holder the combination with two separable members of a hook-and-eye electri'c contact coupling the members together and limiting the distance which they can move apart, of a springpressed contact-plunger on one member, a socket on the other member and a contact for the plunger within the socket substantially as set forth.

3. In an electric-incandescent-lamp holder, two separable members, a set of three contacts on each member one of the contacts in each set being axially arranged and springpressed, and the remaining two contacts on one member situated at unequal distances from the axial contact and consisting of double hooks, for engagement with eye-contacts similarly situated on the other member, substantially as set forth.

In witness whereof I have hereunto set my hand in presence of two witnesses.

EUS'I'AOE GRAHAM SIIEPIA RD.

\Vitnesses:

WALTER E. ROCHE, ROBERT SIMPSON. 

